1. Field of the Invention
The present invention relates to a drawer slide, and more particularly to an interlocking device capable of providing strong structure strength to the linkage member and maintaining other drawers in a locked state when one drawer is being pulled. Furthermore, since the middle board is driven to slide by the inner board.
2. Description of the Prior Art
Cabinets are normally provided with an interlocking device as shown in FIGS. 11-13 in order to prevent other drawers from being opened when one of the drawers is pulled out. The conventional interlocking device comprises an outer board 90 which is formed with an elongated groove 901 and an assembling hole 902 at an end thereof. A clipping piece 91 is disposed in the elongated groove 901 and includes an extending clipping portion 911 which defines a space 912 with respect to the assembling hole 902. The interlocking device further comprises two linkage members 93, each of which includes an L-shaped abutting portion 931, an engaging protrusion 932 and an assembling portion 933. The abutting portions 931 are disposed in the space 912, and the engaging protrusion 932 are inserted into the elongated groove 901 from the assembling hole 902 and restricted therein by the lateral edge of the elongated groove 901. The assembling portions 933 are provided for insertion of linkage rod (now shown) to engage with or move other structures.
As shown in FIGS. 12 and 13, in the outer board 90 are disposed a middle board 94 and an inner board 95. The outer board 90 is disposed in the cabinet, and the inner board 95 is disposed in the drawers. FIG. 12 shows that the inner board 95 is provided at its end close to the linkage members 93 with an actuator 96. The actuator is rhombic-shaped and includes two oblique surfaces 961 tapering toward the inner board 95 and two oblique surface 962 tapering in an opposite direction to the tapering direction of the oblique surfaces 961. The engaging protrusions 932 of the linkage members 93 are each provided with an oblique surface 9321, 9322, and the oblique surfaces 9321, 9322 are tapered in opposite directions.
The four oblique surfaces 961, 962 of the actuator 96 and the oblique surfaces 9321, 9322 of the engaging protrusions 932 of the linkage members 93 cooperate with one another to make the inner board 95 push against the two linkage members 93 when the inner board 95 moves along the with the drawers. However, the upper linkage member 93 as shown in FIG. 12 will fall off and abut against the edge of the inner board 95 after the actuator 96 passes, so that the engaging protrusions 932 of the two linkage members 93 won't be able to abut against the edge of the outer board 90 to move the linkage rod (not shown) and other structures.
To solve the abovementioned problem, another conventional structure was invented as shown in FIG. 13, wherein the actuator 97 is located at one end of the middle board 94 close to the linkage members 93 and extends toward the linkage members 93 to form two swayable clipping arms 971. When the inner board 95 moves through the two clipping arms 971, it will push the two clipping arms 971 toward the two linkage members 93, so as to make the engaging protrusions 932 of the linkage members 93 press against the edge of the outer board 90, so that the linkage rod (not shown) is able to move and engage with other structures.
However, as shown in FIG. 13, the actuator 97 and the clipping arms 971 are integral with each other as an elastic unitary structure made of plastic material, the actuator 97 has a weak structural strength, and the clipping arms 971 are more likely to be broken due to frequent sway motion. Furthermore, the linkage members 93 are positioned by the engaging protrusions 932 pressing against the edge of the outer board 90, however, the engaging protrusions 932 are small and thin to be strong enough to stand the pressing force applied to the edge of the outer board 90 by the actuators 96, 97. The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.